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I was trying out different external Thunderbolt 3 and USB-C enclosures for a 2TB Samsung EvoPlus NVMe SSD.

My goal is to achieve high write/read speed but in a portable package, for the workflows specific to my needs.

A common problem with all these enclosures was that all of them were heating up even when I was doing no I/O with the device. I believe laptops don’t do this, it would be a constant battery drain.

  1. Is this the result of poor controller software or the way SSDs work that requires such a waste of power?
  2. Is there a portable solution that works with a 2TB SSD and gives decent write/read performance?
Giacomo1968
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vach
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    Laptops actually waste a ton of energy to heat. As with any electronic component, inefficiencies are typically dissipated as heat. What question you’re asking is all relative. What you say is warm may not mean anything at all to someone else. But, it is unreasonable to think a powered on electronic device won’t produce any heat. Power saving algorithms try to shut off things that aren’t being used, the same may be possible for your external drives. – Appleoddity Dec 09 '19 at 06:07
  • For a high-performance SSD, you're going to want an all-metal enclosure (I'm partial to [Orico](http://www.orico.cc/us/product/subcategory/535.html)), and you're going to want a small fan blowing on the enclosure if you're doing large file transfers, as the case will get hot enough to burn and eventually the drive will enter thermal protect and auto power-cycle _(I use a tiny USB powered fan that creates just enough airflow my 850 EVO mSATA enclosures don't get hot enough to enter thermal protect.)_ – JW0914 Dec 09 '19 at 06:10
  • I have two Samsung 860 EVO 2 TB SSD drives (not NVMe) in their metal enclosures in plastic carriers in the hard drive locations. They are running at 22 degrees C. The machines runs 7x24 non-stop. – John Dec 09 '19 at 12:39

1 Answers1

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This is not a "waste of power". Power dissipation of SSD depends on traffic intensity. And the traffic intensity depends on the kind of host controller you have, and the kind of USB-to-NVMe bridge you have.

Behind the Type-C connector you will likely have a xHC (eXtensiveHostController) that supports USB 3.1 Gen2 speed (10GBps raw data rate). If you want highest performance, you will need a USB-SSD bridge that supports Gen2 USB speeds as well. More, modern USB Gen2 high-performance controllers will use UASP streaming mode (instead of old BOT - bulk-only transport), and will achieve sustained data rates of 1GBps+.

If you check power consumption of NVMe drives, you will likely see up to 3 A at 3.3V, or close to 10W of dissipated power. This power will be consumed at highest data rate for the device, which is ~1500 MBps for ordinary sticks, like shown below.

enter image description here

9-10W of power is not something to take easy without a heat sink and all-metal enclosure with thermally conductive pads.

The m.2 SATA3 drives, in contrast, can do maybe 540 MBps at most (due to SATA speed bottleneck, which is about half of USB 3.1 Gen2 data rate), so they run much cooler, and usually don't need extra cooling.

AFAIK, only few host platforms on today market can give you fast rates and hot external enclosures. These are host PCIe cards based on ASM2142/3142 chips, and Ryzen-based 2000/3000 class machines from AMD and their channel sources.

Also, heating up of external Type-C devices even in absence of I/O access is likely because the host controller has its LPM (Link Power Management) non-functional (disabled because of some issues with its functionality). Or it could be disabled in the device. So you experience can vary with each particular USB host/device pair.

Ale..chenski
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  • thanks for detailed answer, learned a lot from it :) though my specific case it was a firmware issue, which is why i found so much heat unnatural (and yes it is unnatural), the heat that you and others are pointing out is obvious, but on idle device will not act like a electrical heater. – vach Dec 15 '19 at 05:26
  • in my case i had 970 evo plus samsun ssd of 2TB, and i tried to use it with macos, and apparently this is one in a 1000 cases where ssd is having issue like this, what i had to do is install samsungs magician software and update the firmware of the ssd, after that my thunderbolt 3 enclosure no longer heated up and delivered solid read/write rates.. reads reached all the way 2400mb/s which is what i needed. – vach Dec 15 '19 at 05:28
  • though one thing bothers me, my write rates are around 1100 mb/s which is far from what this ssd is capable of. So i have a question if i may. When ssd is plugged to pcie in a laptop vs external enclosure over usbc/tunderbolt3 cable is there any extra pins that pice has that delivers power and utilizes full power of the hardware? – vach Dec 15 '19 at 05:31
  • because if the number of pins, data lanes is equal i would expect to have very similar sequential read/write speeds... yes latency will be longer but passing data sequentially should be similar... so i would like to know is it hardware disadvantage or software in the controller that does bad job? (latter one could be patched over time) – vach Dec 15 '19 at 05:32